Halohydrins of 2,4-diunsaturated aliphatic carboxylic esters

ABSTRACT

Novel unsaturated aliphatic carboxylic esters substituted at C-4 with a halogen atom, intermediates therefor, and the control of insects.

- [22] Filed:

United States Patent [191 Henrick 1 HALOHYDRINS OF 2,4-DIUNSATURATEDALIPHATIC CARBOXYLIC ESTERS [52] US. Cl 260/408, 260/348 A, 260/405,

260/400, 424/312, 424/318, 424/D1G. 12 [51] Int. Cl C07c 69/66, AOln9/24 [58] Field of Search 260/408 [56] References Cited UNITED STATESPATENTS 3,193,565 6/1965 Tscheschc et a1. 260/408 June 28, 19743,706,733 12/1972 Henrick et a1. 260/327 E Primary ExaminerLewis GottsAssistant ExaminerDiana G. Rivers Attorney, Agent, or FirmDonald W.Erickson; Lee- 'Louise H. Priest [5 7] ABSTRACT Novel unsaturatedaliphatic carboxylic esters substituted at G4 with a halogen atom,intermediates therefor, and the control of insects.

10 Claims, No Drawings IIALOIIYDRINS OF 2,4-DIUNSATURATEI) ALIPIIATICCARBOXYLIC ESTERS This invention relates to new unsaturated aliphaticcarboxylic esters substituted at G4 with a halogen atom, synthesisthereof, intermediates therefore, and the control of insects. Moreparticularly, the new carboxylic esters of the present invention arerepresented by the following fonnula (A):

m is zero, one or two;

n is one, two or three;

X is a halogen atom;

R is hydrogen, lower alkyl, cycloalkyl, aryl or aralkyl;

each of R, R R and R is lower alkyl;

R is hydrogen ormethyl;

Z is hydrogen, lower alkyl, halogen atom, hydroxy lower alkoxy or loweracyloxy; and

Z' is hydrogen or, together with Z, a carbon-carbon bond.

The compounds of formula A are useful for the control of insects. Theutility of these compounds as insect control agents is believed to beattributable to their juvenile hormone activity. They are preferablyapplied to the immature insect, namely, during the embryo, larvae orpupae stages in view of their effect on metamorphosis and otherwisecausing abnormal development leading to death or to inability toreproduce. These compounds are effective control agents forHeteropterans, such as Lygaeidae, Miridae and Pyrrhocoridae;Homopterans, such as Alphididae, Coccidae and Jassidae; Lepidopterans,such as Pyralidae, Noctuidae and Gelechiidae; Coleopterans, such asTenebrionidae, Crysomelidae and Dermestidae; Dipterans, such asCulicidae, Muscidae and Sarcophagidae; and other insects. The compoundscan be applied at low dosage levels of the order of 0.01 ug. to ,ug. perinsect. Suitable carrier substances include liquid or solid inertcarriers, such as water, acetone, xylene, mineral or vegetable oils,talc, vermiculite, natural and synthetic resins and silica. Treatment ofinsects in accordance with the present invention can be accomplished byspraying, dusting or otherwise contacting the insect, directly orindirectly, with one or more compounds of formula A. Generally, aconcentration of less than 25 percent of the active compound isemployed. The formulations can include insect attractants, emulsifyingagents or wetting agents to assist in the application and effectivenessof the active ingredient.

In the description hereinafter, each of R-R X, Z and Z is as definedabove, unless otherwise specified.

In one embodiment of the present invention, the compounds of formula A,wherein Z' ishydrogen, are synthesized according to the followingoutlined method:

acid in an organic solventto form the 4,5-epoxide of formula II. The4,5-epoxide is converted into the halohydrin (III) by treatment with theappropriate hydrogen halide in an organic solvent. The halohydrin (III)is then converted into the corresponding 5-mesylate by treatment withmethanesulfonyl chloride, which is treated with1,S-diazobicyclol5.4.0]undec-5-ene to prepare the4-halo-2,4-diunsaturated ester of formula A (R represents lower alkyl,cycloalkyl, aralkyl or aryl).

In another embodiment of the present invention, 4-halo-2,4-diunsaturatedcompounds and 4-halotriunsaturated compounds (Z together with Z is acarbon-carbon bond) of formula A are prepared by the reaction of aphosphonate of formula IV with an a alde hyde of formula V. Thisreaction is conducted in the presence of a base, such as sodium hydride,in an organic solvent R is lower alkyl).

In another embodiment of the present invention, compounds of formula Aare prepared by ylid reaction using ylid of formula VI in reaction withan aldehyde of formula V. The ylid (VI) can be prepared using theprocedure of Markl, Chem. Ber. 94, 2996 (1961) and ibid., 95, 3003(1962) starting with an ylid of formula VII. R represents aryl, aralkylor cycloalkyl.

Acids of formula A (R is hydrogen) can be prepared by hydrolysis withbase, such as potassium carbonate in an organic solvent, such as alower, alcohol. Other esters of formula A can be prepared by conversionof the acid into the acid halide as by treatment with oxalyl chloride,or the like, and then reaction of the acid halide with the alcoholcorresponding to the ester moiety desired.

The tri-unsaturated esters of formula A (2' together with Z is acarbon-carbon bond) also serve as precursors for compounds of formula Awherein Z is hydrogen and Z is halogen atom, hydroxy, alkoxy or acyloxy.Compounds of formula A wherein Z is halogen atom can be prepared bytreatment of the tri-unsaturated precursor (A) with hydrogen halide inan organic solvent. Compounds of formula A wherein Z is hydroxy can beprepared from the tri-unsaturated precursor by the addition of water tothe terminal olefinic bond using a mercuric salt followed by reductionusing a borohydride, hydrazine or sodium amalgam. By conductingthis'reaction in the presence of an alcohol, such as methanol, ethanolisopropanol, t-butanol, and the like, the corresponding ether (Z isalkoxy) is prepared. See Brown and Rei, J. Am. Chem. Soc. 91, 5646(1969) and Wakabayashi, .1. Med. Chem. 12, 191 Jan. 1969). Compoundsofformula A wherein Z is acyloxy can be prepared from the hydroxyprecursor (A, Z is hydroxy) by reaction with a carboxylic acid chlorideor anhydride.

The di-unsaturated esters of formula l and the aldehydes of formula Vcan be prepared as described in application Ser. No. 187,897 and Ser.No. 187,898, each filed Oct. 8, 1971, now US. Pat. Nos. 3,755,411 and3,752,843 respectively, the disclosures of which are incorporated byreference.

The term lower alkyl, as used herein, refers to a straight or branchedchain saturated aliphatic hydrocarbon group having a chain length of oneto six carbon atoms, e.g., methyl, ethyl, propyl, i-propyl, n-butyl,sbutyl, t-butyl, pentyl and hexyl.

The term cycloalkyl, as used herein, refers to a cyclic alkyl groupcontaining three to eight carbon atoms, e.g., cyclopropyl, cyclopentyland cyclohexyl.

The term aralkyl," as used herein, refers to a monovalent hydrocarbongroup in which a hydrogen atom of a lower alkyl group is substituted byan aryl group, such as benzyl, phenethyl, methylbenzyl, naphthylmethyland naphthylethyl containing from seven to 12 carbon atoms.

The term lower acyloxy, as used herein,,refers to an aliphatichydrocarbon carboxylic acyloxy group of one to six carbon atoms.

The presence of an olefinic bond at position C-2 and G4 of the compoundsof formula A give rise to four isomers, each of which is embraced by thepresent invention. The presence of three olefinic bonds in compounds offormula A give rise to eight isomers, each of which is embraced by thepresent invention. As mentioned above, a mixture of isomers is suitablyemployed for the control of insects, such as a mixture containing thetrans(2), trans(4) isomer and the cis(2), trans(4) isomer. Theconditions of the syntheses described herein and the reactants can beselected so as to favor formation of one isomer, such as the all transisomer, over the formation of other isomers. The selection ofappropriate conditions and reactants to favor formation of one isomerover another will be apparent to those of ordinary skill in the artgiving due consideration to the specific examples hereinafter. In thespecific examples hereinafter, when isomerism is not specified, it isunderstood to include a mixture of isomers which, if desired, can beseparated using known separation methods.

The following examples are provided to illustrate the practice of thepresent invention. Temperature is given in degrees Centigrade.

The term halogen atom, as used herein, refers to bromo, chloro, fluoroand iodo.

EXAMPLE I To 15 g. of ethyl 3,7,1l-trimethyldodeca-2,4- dienoate in ml.of methylene chloride is slowly added'l2.6 g. of 85 percentm-chloroperbenzoic acid in ml. of methylene chloride with stirring andmaintaining temperature at about 25. After addition is complete, thereaction mixture is left at room temperature for four days. Sodiumbicarbonate (5 percent) is added and the mixture extracted with ether.The organic phase is washed with 5 percent sodium bicarbonate, water andbrine, dried over calcium sulfate and solvent removed under reducedpressure to yield ethyl 4,- 5-oxido-3,7,1 1-trimethy1dodec-2-enoate,which can be purified by thin-layer chromatography eluting withether/hexane (l/3).

Following the process of this example, ethyl 4,5- oxido-ll-methoxy-3,7,l l-trimethyldodec-2-enoate is prepared from ethyl1l-methoxy-3,7,l l-trimethyldodeca-2,4-dienoate.

H EXAMPLE 2 To 1.4 .ml. of concentrated hydrochloric acid (37 percent)is added 2 g. of ethyl 4,5-oxido-3,7,l1-

trimethyldodec-Z-enoate in 20 ml. of anhydrous ether, with stirring,below 5. Stirring is continued for three hours. Excess HCl isneutralized with solid sodium carbonate. The aqueous layer is saturatedwith ammonium sulfate, separated and extracted with ether. The ethersolutions are combined, washed with 5 percent ammonium sulfate, driedover sodium sulfate and concentrated. The concentrate is diluted withether and chromatographed on one meter plates eluting with ether/-hexane (l/5) to give ethyl 4-chloro-5-hydroxy-3,7,lltrimethyldodec-Z-enoate.

By use of the above process, ethyl ll-methoxy-4- chloro-5-hydroxy-3,7,ll-trimethyldodec-Z-enoate is prepared from ethyl l1-methoxy-4,5-oxido-3,7,1 ltrimethyldodec-2-enoate.

EXAMPLE 3 Methanesulfonyl chloride (0.43 ml.) is added to a solution of0.9 g. of ethyl 4-chloro-5-hydroxy-3,7,lltrimethyldodec-2-enoate and0.43 g. of triethylamine in 30 m1. of methylene chloride at 0. Thereaction mixture is stirred for 1 hour. The mixture is diluted withmethylene chloride, washed with ice water, 10 percent HC] solution,saturated sodium bicarbonate solution and brine, dried over calciumsulfate and solvent evaporated under reduced pressure to yield ethyl4-chloro- 5-methanesulfonyloxy-3,7,l l-trimethyldodec-- -2-enoate, whichcan be purified by thin-layer chromatography.

In the same way, ethyl 4-chloro-5- methanesulfonyloxy-l l-methoxy-3,7,1l-trimethyldodec-Z-enoate is prepared from ethyl 4-chloro-5- hydroxy-ll-methoxy-3,7,l l-trimethyldodec-2-enoate.

EXAMPLE 4 A mixture of 0.87 g. of ethyl 4-chloro-5-methanesulfonyloxy-3,7,l 1trimethyldodec-2-enoate, 0.34 g. ofl,5-diazobicyclo[5,4.0]undec-5-ene and 30 ml. of dimethylformamide isstirred, under nitrogen, at room temperature for 3 hours. The mixture isdiluted with ether, washed with percent l-lCl, saturated sodiumbicarbonate solution, water and brine, dried over calcium sulfate andsolvent removed under reduced pressure to give ethyl 4-chloro-3,7,ll-trimethyldodeca-2,4-dienoate, which can be purified by thinlayerchromatography eluting with ether/hexane ('l/S).

Ethyl 4-chloro-l l-methoxy-3,7,l l-trimethyldodeca- 2,4-dienoate isprepared from ethyl 4-chloro- Smethanesulfonyloxy-l l-methoxy-3,7,ll-trimethyldodec-2-enoate using the process of this example.

EXAMPLE 5 Diethyl 3-ethoxycarbonyl-2-methylprop-2-enyl phosphonate (0.1mole) is added dropwise, at to a slurry of 0.1 mole of NaH in 400 ml. oftetrahydrofuran. The mixture is stirred about one hour or until hydrogenevolution ceases. Then 0.1 mole of bromine is added dropwise to themixture, with stirring, while cooling in a cooling bath (0 to 20). Atabout 0, additional NaH (0.] mole) is added and stirred until evolutionof hydrogen ceases. Then 0.1 mole of 3,7-dimethyloct-6- en-l-al is addeddropwise and left overnight at room temperature. The reaction mixture isworked up by washing with water, extracting with ether, drying overcalcium sulfate, and evaporation of solvent under reduced pressure togive ethyl 4-bromo-3,7,l l-trimethyldodeca-2,4,l0-trienoate, which canbe purified by chromatography, if desired.

By repeating the process of this example using chlorine in place ofbromine, there is prepared ethyl 4- chloro-3,7,l l-trimethyldodeca-2,4,l O-trienoate.

EXAMPLE 6 Following the procedure of Example 1, each of the esters underColumn 1 is epoxidized to prepare the respective 4,5-epoxide underColumn ll:

isopropyl 3,7,1 l-trimethyldodeca-2,4-dienoate, ethyl 3,7,10, ll-tetramethyldodeca-2,4-dienoate, ethyl 3,7,1l-trimethyltrideca-2,4-dienoate,

ethyl 3,7,10-trimethylundeca-2,4-dienoate,

ethyl 3,7,10-trimethyldodeca-2,4-dienoate,

isopropyl l l-methoxy-3,7, l l-trimethyldodeca-2,4- dienoate,

isopropyl 1 l-methoxy-3,7,l l-trimethyltrideca-2,4-

dienoate,

6 ethyl l l-methoxy-3,7, l 0, l 1-tetramethyldodeca-2,4-

dienoate,

ethyl l l-chloro-3,7,l ltrimethyldodeca-2,4-dienoate,

ethyl l0-methoxy-3,7, l0-trimethylundeca-2,4- dienoate, ethyl dienoate,

ethyl 3, l l-dimethyl-7-ethyltrideca-2,4-dien0ate.

isopropyl 4,5-oxido-3 ,7,l l-trimethyldodec-2-enoate,

l l-acetoxy-3,7,1 l-trimethyldodeca-2,4-

4,5-oxido-3,7, 10- 1 l-tetramethyldodec-Z- 4,5-oxido-3,ll-dimethyl-7-ethyltridec-2- EXAMPLE 7 Using the process of Example 2,each of the epoxides under Column ll is converted into the respectivechlorohydrin under Column Ill:

lIl

isopropyl 4-chloro-5-hydroxy-3,7,l l-trimethyldodec-Z-enoate,

ethyl 4-chloro-5-hydroxy-3,7, 10,1 l-tetramethyldodec-2-enoate,

ethyl 4-chloro-5-hydroxy-3,7,l l-trimethyltridec-Z- enoate,

ethyl 4-chloro-5-hydroxy-3,7, l O-trimethylundec-Z- enoate,

ethyl 4-chloro-5-hydroxy-3,7, l O-trimethyldodec-Z- enoate,

isopropyl 4-chloro-5-hydroxy-l l-methoxy-3,7, l 1-trimethyldodec-2-enoate,

isopropyl 4-chloro-5-hydroxy-l l-methoxy-3,7, lltrimethyltridec-2-enoate,

ethyl 4-chloro-5-hydroxy-l l-methoxy-3,7, l 0, lltetramethyldodec-2-enoate,

ethyl 4-chloro-5-hydroxy-l l-chloro-3 ,7, l ltrimethyldodec-2-enoate,

ethyl 4-chloro-5-hydroxy- 1 0-methoxy-3,7, l0- trimethylundec-Z-enoate,

ethyl 4-chloro-5-hydroxy-l l-acetoxy-3,7,1 1-

trimethyldodec-Z-enoate,

ethyl 4-chloro-5-hydroxy-3,l l-dimethyl-7-ethyltridec-2-enoate.

By use of the process of Example 3, each of the chlorohydrins underColumn Ill is converted into the respective S-mesylate', which is usedin the process of Example 4 to prepare the respective4-chloro-2,4-diunsaturated compound under Column 1V.

isopropyl 4-chloro-3,7, 1 1-trimethyldodeca-2,4- dienoate,

ethyl 4-chloro-3,7, l 0,1 l-tetramethyldodeca-2,4-

dienoate,

ethyl 4-chloro-3,7,l 1-trimethyltrideca-2,4-dienoate,

ethyl 4-chloro-3,7,10-trimethylundeca-Z,4-dienoate,

ethyl 4-chloro-3,7,10-trimethyldodeca2,4-dienoate,

isopropyl 4-chloro-l 1-methoxy-3 ,7,1 l trimethyldodeca-2,4-dienoate,

isopropyl 4-chloro-l l-methoxy-3,7,1 l-trimethyltrideca-2,4-dienoate,

ethyl 4chloro-1 l-methoxy-3,7,10,1 l-tetramethyldodeca-2,4-dienoate,

ethyl 4,1 1 -dichloro-3,7, 1 1-trimethyldodeca-2,4 dienoate,

ethyl 4-chlorol -methoxy-3,7, IO-trimethylundeca- 2,4-dienoate,

ethyl 4chloro-l l-acetoxy-3,7,l l-trimethyldodeca- 2,4-dienoate,

ethyl 4-chloro-3,1 l-dimethyl-7-ethyltrideca-2,4- dienoate.

EXAMPLE 8 The process of Example is repeated using each of 3,7-dimethylnon-6-en- 1 -al, 3,7-dimethyloctanl-al, 3,7,7,-trimethyloctan- 1 -al, 7-hydroxy-3,7- dimethyloctan-l-al,3,6-dimethylhept-5-en-l-al, 3,6,7-trimethylo'ct-6-en- 1 -al,6-hydroxy-3,6-dimethylheptan- 1 -al and 7-hydroxy-3,6,7-trimethyloctan-1 -al as the aldehyde reactant in place of 3,7-dimethyloct-6-enl-al toprepare the respective 4-bromo-2,4-diunsaturated ester under Column V.

4-bromo-3,7, l 0-trimethylundeca-2,4,9-

EXAMPLE A mixture of 4.5 g. of ethyl4-chloro-3,7,1ltrimethyldodeca-Z,4-dienoate, 35 ml. of ethanol, 10 ml.of water and 7 ml. of 50 percent aqueous sodium hydroxide is refluxedfor about 16 hours. The mixture is then diluted with water, neutralizedand extracted with ether. The organic phase is washed with water, driedand evaporated to yield 4-chloro-3,7,l l-trimethyldodeca-2,4-dienoicacid.

By use of the process of this Example, other acids of formula A can beprepared by hydrolysis of the respective ester of formula A.

EXAMPLE 10 EXAMPLE 1 1 To a solution of 2.0 g of ethyl4-chloro-3,7,lltrimethyldodeca-2,4,IO-trienoate in 30 ml. of ethanol,cooled in an ice bath, is slowly added 5.2 g. of acetyl chloride. Thereaction mixture is allowed to rise to room temperature and then stirredfor about 60 hours. The mixture is concentrated under reduced pressureand then poured into water/hexane. The organic layer is separated,washed with aqueous sodium bicarbonate, water and brine, dried overcalcium sulfate and solvent removed to yield ethyl 4,1 l-dichloro-3,7,1l-trimethyl- Y dodeca-2,4-dienoate.

EXAMPLE 12 To 0.5 .g. of4-chloro-1lmethoxy-3,7,1l-trimethyldodeca-2,4-dienoic acid in 10 ml. ofbenzene, under nitrogen, is added 0.17 ml. of oxalyl chloride. Themixture is stirred for about one hour and then allowed to stand 1.5hours. Two ml. of isobutanol is added. After three hours, ether isadded. The mixture is washed with aqueous sodium bicarbonate, water andbrine, dried over calcium sulfate and concentrated under reducedpressure to yield isobutyl 4-chloro-1l-methoxy-3,7,1 1-trimethyldodeca-2,4-dienoate.

Using each of t-butanol, cyclopentanol, benzyl alcohol, phenol,s-butanol and methanol in the above process, there is prepared:

t-butyl 4-chloro-l l-methoxy-3 ,7,l l-trimethyldodeca-2,4-dienoate,

cyclopentyl 4-chloro-1 l-methoxy-3,7,l l-trimethyldodeca-2,4-dienoate,

benzyl 4-chloro-l l-methoxy-3 ,7,l l-trimethyldodeca-2,4-dienoate,

phenyl 4-chloro-l 1-methoxy-3 ,7, l 1 -trimethyldodeca-2,4-dienoate,

s-butyl dodeca-2,4-dienoate,

methyl 4-chloro- 1 l -methoxy-3 ,7, l l-trimethyldodeca-2,4-dienoate.

EXAMPLE 13 To an ice cold solution of 2.0 g. of isopropyl 4-chloro-3,7,1'1-trimethyldodeca-2,4,lO-trienoate in ml. of isopropanol isadded 2.29 g. of mercuric acetate over about 15 minutes. The mixture isstirred at ice temperature for 3 hours and then at room temperature4-chloro-l l-methoxy-3,7,l l-trimethylfor about 17 hours. A solution of1.21 g. of potassium hydroxide, ml. of water, and 20 ml. of isopropanolis then added to the mixture cooled in an ice bath. Then 0.126 g. ofsodium borohydride is added in small portions and stirring continued forone hour. The mixture EXAMPLE 14 A solution of 0.1 mole oftriphenylphosphine 3- ethoxy-carbonyll -chloro-2-methylprop-2-ene(prepared from triphenylphosphine-3-ethoxycarbonyl-2- methylprop-2-eneusing phenyl iodide chloride in triethylamine by the method of M'eirkl,supra) and 0.1 mole of 3,7-dimethyloct-6-en-l-al in toluene, undernitrogen, is refluxed about 6 hours. Toluene is removed under reducedpressure, pentane added and the mixture filtered. The filtrate (combinedwith pentane washings) is evaporated under reduced pressure to yieldethyl 4-chloro-3,7,ll-trimethyldodeca-2,4,10- trienoate, which can bepurified by chromatography.

Other aldehydes of formula V, such as the aldehydes of Example 8, aresuitable starting materials for the process of this Example.

EXAMPLE The process of Example 2 is repeated using HF in place of HCl toprepare ethyl 4-fluoro-5-hydroxy- 3.7,]l-trimethyldodec-2-enoate and,similarly, ethyl 4-fluoro-5-hydroxy-l l-meth0xy-3,7,ll-trimethyldodec-Z-enoate. Each of these fluorohydrins is converted intothe respective S-mesylate and then used in the process of Example 4 toprepare ethyl 4-fluoro-3,7,l 1- trimethyldodeca-2.4-dienoate and ethyl4-fluoro-llmethoxy-3,7,l l-trimethyldodeca-2,4-dienoate, respectively.

EXAMPLE l6 Triphenylphosphine-3-ethoxycarbonyll -iodo-2-methylprop-2-cne (prepared by the method of Mark], supra, fromtriphenylphosphinc-3-ethoxycarbonyl-2- methylprop-2-ene using elementaliodine) is reacted with each of 3,7-dimethyloctan-l-al and 7-methoxy-3.7-dimcthyloctanl -a] using the procedure of Example 10 14 to produceethyl 4-iodo-3,7,ll-trimethyldodeca- 2,4-dienoate and ethyl4-iodo-l1-methoxy-3,7,l1- trirriethyldodeca-Z,4-dienoate, respectively.

What is claimed is:

l. A compound selected from those of the formula:

a Ra a Rt- R-ddH- om)ron-onr-cn-on-lion-d-on' wherein,

n is one or two; R is lower alkyl, cycloalkyl, aryl or aralkyl; each ofR, R, R and R is methyl or ethyl; R is hydrogen or methyl; X is ahalogen atom; and Z is hydrogen, chloro, hydroxy, lower alkoxy or loweracyloxy.

2. A compound according to claim 1 wherein R is methyl and Z is hydrogenor lower alkoxy of one to four carbon atoms.

3. A compound according to claim 2 wherein each of R R and R is methyl;n is two; Z is hydrogen, methoxy or ethoxy; and X is bromo or chloro.

4. A compound according to claim 3 wherein X is chloro and R is loweralkyl of one to four carbon atoms.

trimethyldodec-2-enoate, according to claim 4.

6. The compound, ethyl 4-chloro-5-hydroxy-l lmethoxy-3,7,ll-trimethyldodec-2-enoate, according to claim 4.

7. The compound, isopropyl 4-chloro-5-hydroxy-l lmethoxy-3,7,lI-trimethyldodec-2-enoate, according to claim 4.

8. A compound according to claim 1 wherein n is two; each of R, R and Ris methyl; R is methyl or ethyl; X is chloro; R is ethyl or isopropyl;and Z is hydrogen or methoxy.

9. A compound according to claim 1 wherein n is one; each of R, R and Ris methyl; R is methyl or ethyl; R is hydrogen; X is chloro; Z ishydrogen or methoxy; and R is ethyl.

10. A compound according to claim 1 wherein n is two; each of R, R R, Rand R is methyl; R is ethyl;

Z is hydrogen or methoxy; and X is chloro.

2. A compound according to claim 1 wherein R1 is methyl and Z ishydrogen or lower alkoxy of one to four carbon atoms.
 3. A compoundaccording to claim 2 wherein each of R2, R3 and R4 is methyl; n is two;Z is hydrogen, methoxy or ethoxy; and X is bromo or chloro.
 4. Acompound according to claim 3 wherein X is chloro and R'' is lower alkylof one to four carbon atoms.
 5. The compound, ethyl4-chloro-5-hydroxy-3,7,11-trimethyldodec-2-enoate, according to claim 4.6. The compound, ethyl4-chloro-5-hydroxy-11-methoxy-3,7,11-trimethyldodec-2-enoate, accordingto claim
 4. 7. The compound, isopropyl4-chloro-5-hydroxy-11-methoxy-3,7,11-trimethyldodec-2-enoate, accordingto claim
 4. 8. A compound according to claim 1 wherein n is two; each ofR1, R2 and R3 is methyl; R4 is methyl or ethyl; X is chloro; R'' isethyl or isopropyl; and Z is hydrogen or methoxy.
 9. A compoundaccording to claim 1 wherein n is one; each of R1, R2 and R3 is methyl;R4 is methyl or ethyl; R5 is hydrogen; X is chloro; Z is hydrogen ormethoxy; and R'' is ethyl.
 10. A compound according to claim 1 wherein nis two; each of R1, R2, R3, R4 and R5 is methyl; R'' is ethyl; Z ishydrogen or methoxy; and X is chloro.